Quantum dots are man-made nano-scale crystals with a particle size generally less than 10nm, and are also called "semiconductor nanocrystals". It is composed of nanoparticles of group II-VI or III-V elements. The optical, electrical, and thermal properties of nanoparticles are significantly different from those of macroscopic materials, such as quantum confinement effects, surface effects, and quantum size effects. This makes it have special potential application prospects as new luminescent materials, photocatalytic materials, and photosensitive sensors. Quantum dot solar cells are a type of solar cells that use quantum dots as absorptive photovoltaic materials, which can be used to replace larger materials such as silicon and copper indium gallium selenide. The combination of quantum dots and solar cells can give solar cells new performance. Quantum dots can make solar cells absorb light of a specific wavelength by changing the size of semiconductor quantum dots, that is, small quantum dots absorb short-wavelength light, and a large number of sub-dots absorb long-wavelength light. This makes it widely used in solar cells and can greatly improve the photoelectric conversion rate of quantum dot solar cells. Compared with traditional solar cells, quantum dot solar cells have certain advantages in terms of price, synthesis method, stability, and photoelectric conversion efficiency.
Figure 1. Structure and working mechanism for the quantum dot solar cell